1. Field of the Invention
The field of the present invention is related to an apparatus for automatically generating accompaniment sounds for music. The accompaniment sounds to be generated are percussion sounds such as cymbal sounds and drum sounds, and melodious sounds such as arpeggio sounds and bass sounds.
2. Prior Art
Automatic accompaniment sound-generating apparatuses have been used for automatically generating accompaniment sounds to accompany musical sounds played by musicians. An automatic accompaniment sound-generating apparatus generates accompaniment sounds according to instruction given by the operator and are based on information about accompaniment pattern, tempo, etc., stored therein.
A conventional automatic accompaniment sound-generating apparatus typically comprises an accompaniment-pattern memory, a tempo-setting means, a reading means, and an accompaniment signal generator. The accompaniment-pattern memory stores information about accompaniment patterns for percussion sounds and melodious sounds according to which the accompaniment sounds are generated. In the production of percussion sounds, the information comprises the generation timing pattern and the sounds which correspond to percussion musical instruments such as cymbals, drums, etc. In the production of melodious sounds, the information comprises generation timing, sound pitch, and tone color, corresponding to melodious musical instruments such as the piano, guitar, etc. The tempo-setting means sets the tempo, according to which the speed of the accompaniment sound generation is controlled. The reading means reads out the information stored in the accompaniment-pattern memory at a speed indicated by the tempo stored in the tempo-setting memory. The accompaniment sound generator generates accompaniment sounds according to the accompaniment pattern information read out by the reading means.
A problem of the conventional automatic accompaniment sound-generating apparatus is that the accompaniment sounds generated by the apparatus tend to be monotonous because the accompaniment pattern is unchanged even when the tempo is changed. Another problem is that the accompaniment sounds sometime become too infrequent and thereby uninteresting when the tempo is slow. Conversely, when the tempo is fast, the accompaniment sounds tend to overlap and interfere one another. Therefore, the operator had to alter accompaniment patterns according to the tempo in order to avoid the problems mentioned above. Furthermore, if various accompaniment patterns are to be stored to avoid the inconvenience mentioned above, the memory necessary for it becomes enormous and impractical.